Matriz 4 x 4, Sumatoria Final

PROGRAM Matriz;
USES wincrt;
CONST
f=4;
c=4;
type
K= ARRAY[1..f,1..c] of INTEGER;
VAR
 arr:K;
 i,j,suma:INTEGER;
BEGIN
suma:=0;
ClrScr;
FOR i:=1 TO f DO
FOR j:=1 TO c DO
BEGIN
readln(arr[i,j]);
IF arr[i,j]>0 THEN
suma:=suma +arr[i,j];
END;
for i:=1 to f do
begin
for j:=1 to c do
write( arr[i,j]:6);
writeln;
end;
WRITELN('SUMA  TOTAL: ', suma);
END.